<template>
  <div style="margin-top: 16px">
    <a-form-item label="消息实例">
      <div
          style="
          display: flex;
          align-items: center;
          justify-content: space-between;
          flex-wrap: nowrap;
        "
      >
        <a-select
            v-model="bindMessageId"
            @change="updateTaskMessage"
        >
          <a-select-option
              v-for="id in Object.keys(messageMap)"
              :key="id"
              :value="id"
          >
            {{ messageMap[id] }}
          </a-select-option>
        </a-select>
        <a-button
            size="small"
            type="primary"
            icon="plus"
            style="margin-left: 8px"
            @click="openMessageModel"
        />
      </div>
    </a-form-item>
    <a-modal
        :visible="messageModelVisible"
        title="创建新消息"
        width="400px"
        destroy-on-close
        @close="messageModelVisible = false"
    >
      <a-form
          :label-col="{ span: 6 }"
          :wrapper-col="{ span: 18 }"
          :model="newMessageForm"
      >
        <a-form-item label="消息ID">
          <a-input
              v-model="newMessageForm.id"
              allow-clear
          />
        </a-form-item>
        <a-form-item label="消息名称">
          <a-input
              v-model="newMessageForm.name"
              allow-clear
          />
        </a-form-item>
      </a-form>
      <template slot="footer">
        <a-button
            size="small"
            type="primary"
            @click="createNewMessage"
        >
          确 认
        </a-button>
      </template>
    </a-modal>
  </div>
</template>

<script>
export default {
  name: 'ReceiveTask',
  props: {
    id: String,
    type: String
  },
  data() {
    return {
      bindMessageId: '',
      newMessageForm: {},
      messageMap: {},
      messageModelVisible: false
    }
  },
  watch: {
    id: {
      immediate: true,
      handler() {
        this.$nextTick(() => this.getBindMessage())
      }
    }
  },
  created() {
    this.bpmnMessageRefsMap = Object.create(null)
    this.bpmnRootElements =
      window.bpmnInstances.modeler.getDefinitions().rootElements
    this.bpmnRootElements
      .filter((el) => el.$type === 'bpmn:Message')
      .forEach((m) => {
        this.bpmnMessageRefsMap[m.id] = m
        this.$set(this.messageMap, m.id, m.name)
      })
    this.$set(this.messageMap, '-1', '无') // 添加一个空对象，保证可以取消原消息绑定
  },
  beforeDestroy() {
    this.bpmnElement = null
  },
  methods: {
    getBindMessage() {
      this.bpmnElement = window.bpmnInstances.bpmnElement
      this.bindMessageId =
        this.bpmnElement.businessObject?.messageRef?.id || '-1'
    },
    openMessageModel() {
      this.messageModelVisible = true
      this.newMessageForm = {}
    },
    createNewMessage() {
      if (this.messageMap[this.newMessageForm.id]) {
        this.$message.error('该消息已存在，请修改id后重新保存')
        return
      }
      const newMessage = window.bpmnInstances.moddle.create(
        'bpmn:Message',
        this.newMessageForm
      )
      this.bpmnRootElements.push(newMessage)
      this.$set(
        this.messageMap,
        this.newMessageForm.id,
        this.newMessageForm.name
      )
      this.bpmnMessageRefsMap[this.newMessageForm.id] = newMessage
      this.messageModelVisible = false
    },
    updateTaskMessage(messageId) {
      if (messageId === '-1') {
        window.bpmnInstances.modeling.updateProperties(this.bpmnElement, {
          messageRef: null
        })
      } else {
        window.bpmnInstances.modeling.updateProperties(this.bpmnElement, {
          messageRef: this.bpmnMessageRefsMap[messageId]
        })
      }
    }
  }
}
</script>
